INTRAMOLECULAR HYDROGEN SITE EXCHANGE IN AN HRU(SIHPH(2)) MOIETY

RuH(Ph)(CO)L(2) (L = P(t)Bu(2)Me) reacts with SiH(2)Ph(2) to give firs t benzene and RuH(SiHPh(2))(CO)L(2), and then RuH3(SiHPh(2))(CO)L(2) a nd Ru(H)(2)(CO)L(2), the trihydride being formed by a dehydrogenative silane coupling reaction when excess SiH(2)Ph(2) is present. Variable- temperature spin saturation transfer experiments reveal exchange betwe en H-a and H-b in RuHa(SiH(b)Ph(2))(CO)L(2); this occurs both by an in tramolecular mechanism and (when SiH(2)Ph(2) is present) by a mechanis m dependent on SiH(2)Ph(2) concentration. Spin saturation transfer als o reveals exchange between all three of the above complexes via additi on/loss of SiH(2)Ph(2) or H-2.